Apparatus for delivering part quantities of foam stock

ABSTRACT

An apparatus for delivering part quantities of foam stock and the like has a feed roller which rotates intermittently and projects into a stock container. The invention is particularly characterized by the provision of a sealing hollow plunger strip with cylinder bores adapted to be connected to delivery chambers of a transfer molding device having a valve spool movable transversely to the cylinder bores.

United States Patent van der Buylton-Domgraff et al.

[ July 22, 1975 APPARATUS FOR DELIVERING PART QUANTITIES OF FOAM STOCK Inventors: Ralph van der Buylton-Domgraff,

Blucherstrasse 23, 3167 Burgdorf, Germany; Alfred Doderer-Winkler, Tannenweg 22, 5451 Melsbach, Germany Filed: on. 2, 1973 Appl. No.: 402,712

Foreign Application Priority Data Oct. 2, 1972 Germany 2248235 US. Cl. 222/162; 222/267; 222/309;

222/254 Int. Cl B67d 5/52 Field of Search 222/254, 255, 267, 226,

References Cited UNITED STATES PATENTS 6/1950 Perkins 222/255 2,857,082 10/1958 Perkins 222/255 3,193,156 7/1965 Egee et al 222/255 3,295,722 l/l967 Gordon et al..... 222/379 X 3,695,486 10/1972 Warner 222/162 FOREIGN PATENTS OR APPLICATIONS 551,480 6/1926 Germany 222/255 Primary Examiner-llobert B. Reeves Assistant Examiner-David A. Scherbel Attorney, Agent, or 'FirmV. Alexander Scher [57] ABSTRACT An apparatus for delivering part quantities of foam stock and the like has a feed roller which rotates intermittently and projects into a stock container. The invention is particularly characterized by the provision of a sealing hollow plunger strip with cylinder bores adapted to be connected to delivery chambers of a transfer molding device having a valve spool movable transversely to the cylinder bores.

4 Claims, 4 Drawing Figures P'A'TENTED JUL 22 m5 SHEET APPARATUS FOR DELIVERING PART QUANTITIES OF FOAM STOCK This invention relates to an apparatus for delivering part quantities of foam stock and similar sensitive stock from a stock container which can be reciprocated relative to an extrusion device and has a feed roller which rotates intermittently and projects partially into the lower part of the stock container and with a die nozzle which is provided at the delivery end of the stock container.

The German Pat. No. 546,882 discloses an apparatus for delivering part quantities of foam stock and similar sensitive stock with a roller disposed in the lower part of a stock container and adapted to slide against a second roller which is non-slidable but pivotable.

It also discloses a feed element and an extrusion device with a die nozzle. To this end the stock container is connected to one feed element, namely the feed roller, the stock container together with the feed element being movable with respect to the other feed element. In this system the stock is delivered through nozzles which are disposed adjacently at a distance from each other in a plate.

This known device has a number of disadvantages. Experience shows that part of the nozzles are clogged by the stock during operation. As a consequence, the stock which is supplied by the feed elements is directed only into the free nozzles, that is to say those which have not been blocked. Since the delivered stock volume remains constant it follows that the mouldings produced by the system become overdimensioned and are therefore heavier than originally calculated. This results in a reduction of profits. Moreover, there will be no mouldingsat all at the positions on the delivery means on which the mouldings are delivered and which are associated with the blocked nozzles. Further processing and finishing of the mouldings is thus substantially and adversely affected.

Frequent cleaning of the nozzles is essential owing to the risk of blockage. This leads to intolerable downtimes which have a detrimental effect on the performance of the apparatus.

The consequence of these numerous disadvantages and defects is that the known apparatus is unable to satisfy practical requirements, not even approximately so.

The same considerations apply in the corresponding sense to the apparatus which is disclosed in the German Pat. No. 551,480.

The German Pat. No. 1,075,931 discloses a transfer moulding machine for producing mouldings in the foodstuffs and allied trade. This machine is provided with a stock container the lower zone of which is closable by a rotary valve. The rotary valve is provided with a plurality of suction grooves and a corresponding number of delivery grooves which define the metering of metering cylinder chambers in conjunction with the receiver space or inlet ducts to the nozzles alternately after rotation of the valve through a defined angle. A delivery plunger is slidably supported in each of the metering cylinder chambers. In one operation position there is communication between the receiver via the suction grooves and each metering cylinder chamber in which the corresponding delivery plunger is moved into the suction position. This causes a negative pressure to be produced in the stock delivery duct to cause the said duct to be filled with stock.

After the appropriate delivery plunger has reached its dead-centre position the rotary valve is pivoted into a position in which communication between the stock receiver and the delivery duct is interrupted but communication between the delivery duct and the .crossflow chamber and therefore to the nozzles is established. Moving the delivery plunger into the other dead-centre position causes the stock to be directed into the cross-flow chamber and from there into the nozzles. Y

The sequence of the suction operation or the delivery operation respectively is a disadvantage in this system. This means that delivery cannot commence until the suction process is completed and the stock receiver is closed by the rotary valve. The output of this known device is therefore naturally greatly reduced.

An object of the present invention is to improve the above-described prior art devices and their operation.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide a sealing hollow plunger strip which is slidingly supported in the nozzle piece by means of cylinder bores which are parallel to each other and are disposed at a distance from each other and are connectable to delivery chambers of the transfer moulding device; the transfer moulding device is provided with a valve spool which is movable, transversely to the aforementioned cylinder bores, and is adapted to interrupt or establish in one or the other limiting position communication between the'cylinder bores which are under negative pressure during the stock discharge operation and the appropriate delivery chambers respectively.

Owing to the construction according to the present invention the suction operation overlaps the delivery operation since stock is drawn in already during the delivery operation. This timed overlap between the two operating processes is naturally reflected in a higher output which it is desired to achieve under practical conditions.

In a further embodiment of the present invention the valve spool is provided with ducts or intermcdiately disposed ports which extend transversely to the longitudinal orientation of the said spool and are associated with the cylinder bores and through which the foam stock is supplied to the delivery chambers of the transfer moulding device or is introduced by the delivery plungers into a die plate.

The transfer moulding device is appropriately pivotably supported on a rise-and-fall frame.

Guide bars along which the stock container is slidingly guided are preferably disposed on both sides of the transfer moulding device.

According to another feature of the present invention the length ofstroke of the stock container is variable.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing by way of example only, a preferred embodiment of the inventive idea.

In the drawings:

FIG. 1 is a side view, partly in section, of a device of the present invention.

FIG. 2 is similar to FIG. 1 but shows the device in a different operating position.

FIG. 3 is partly a side view and partly a section along the line II of FIG. 2. 7

FIG. 4 is partly a plan view and partly a section along the line II-II of FIG. 1.

The device shown in the drawings includes a stock container 1 which holds the foam stock, for example sugar foam, for processing into so-called chocolatecovered marshmallows and the like. The stock is to be delivered into a transfer moulding device 2 which is disposed transversely to the stock container 1.

To this end the lower part of the stock container 1 is provided with an intermittently rotating feed roller 3 whose function and method of operation will be described hereinbelow.

A rectangular nozzle member 5 which is disposed at the delivery end 4 of the stock container 1 is adapted to receive a hollow piston strip 11 into which a specific number of cylindrical bores have been worked.

The transfer moulding device 2 in the illustrated embodiment comprises delivery chamber 7, coordinated in pairs, disposed in a cylinder block 6 and having delivery plungers 8 slidingly guided therein and connected to a cross-member 9.

A valve spool 10 is slidingly supported in the transfer moulding device 2.

The hollow plunger strip 11 is slidingly guided in the nozzle member 5, the said hollow plunger strip 11 being fixed to the transfer moulding device. The dimensions of each hollow plunger are such that the plunger is supported in the cylinder bores of the nozzle member 5 so as to slide therein but in well sealing manner. Grooves or flutes may be worked into the hollow plunger where appropriate to function as a labyrinth sea].

A die plate 12 is supported below the valve spool 10 and is adapted for delivering the foam stock. The valve spool 10is provided with ducts 10a or intermediate ports 10b which extend transversely to the longitudinal direction of the spool and are associated with the cylinder bores for supplying foam stock to the delivery chamber 7 of the transfer moulding device 2 or for the introduction of such foam stock from the delivery plungers 8 into the die plate 12. Conveniently, the die plate 12 is interchangeable to avoid difficulties in producing goods of different shape and size.

As shown in FIGS. 1 to 4, the transfer moulding device 2 is pivotably supported on a rise-and-fall frame 13. Pivotable supporting is performed by bearings 14 which are mounted on the frame 13 and which are connected to the cross-member 9 of the transfer moulding device 2, as shown in FIG. 4.

Guide rods 15 along which the stock container 1 is slidingly guided by corresponding bearings 16 are provided on both sides of the transfer moulding device 2. This method of supporting the stock container 1 and the transfer moulding device 2 ensures that the nozzle member 5 and the hollow plunger strip 11 which projects therein are always coaxially supported with respect to each other so that leakages are substantially eliminated.

The motion of the stock container 1 in the illustrated embodiment towards the transfer moulding device 2 or in the opposite direction is performed by means of piv oting levers 17 which are mounted on a shaft 18 that is supported in the frame 13. The pivoting motion of said shaft 18 is performed by means'of sliding block levers 19 which also permit a stepless variation of the length of stroke of the stock container 1 to be obtained.

The sliding block lever 19 is driven by gearwheels 20, 21, 22, the gearwheel 22 being driven via a toothed chain 23 and a pinion 24 by a drive 25. The transmission and drive elements illustrated in the drawing have merely a symbolic character since the means for obtaining the pivoting motion for the pivoting lever 17 are a matter for the expert. It is evident that this motion can also be obtained by other means.

The valve spool 10 is operated by pivoting levers 26 and the cam 27 in conjunction with the toothed chain 23 in the manner described hereinbelow, namely in synchronism with the other elements.

The delivery plunger 8 is operated by the crossmember 9 and the linkage 28 as well as through the sliding block levers 29 and the gearwheels 21, 22. A conveyor belt 30 is supported in a stationary position below the transfer moulding device 2 and is driven by a drive 25 via an indexing mechanism 31.

The frame 13 is raised and lowered together with the stock container 1, the transfer moulding device 2, the lever system 32, the control cam 33 and the driving element 34 by the drive 25. After completion of the discharge operation these motions relative to the conveyor belt 30 ensure better tear-off of the foam stock or the like which is discharged from the die plate 12.

The device according to the invention operates as follows:

During the motion of the stock container from the position illustrated in FIG. 2 into that illustrated in FIG. 1, that is to say during the motion of the stock container 1 to the left in the drawing, the valve spool 10 interrupts communication between the hollow plunger and the delivery chambers 7 of the transfer moulding device 2 (FIG. 1). As a result of this motion of the stock container 1 to the left in the drawing a vacuum is produced in the nozzle member 5, that is to say at the delivery end 4 of the stock container 1, the magnitude of said vacuum being defined by the length of stroke of the aforementioned stock container 1. During this motion of the stock container 1 the feed roller 3 is rotated by the linkage 35 in the clockwise direction so that the vacuum which is formed but also the rotating motion of the aforementioned feed roller 3 cause the stock to be conveyed into the hollow plunger. In this position (FIG. 1) the valve spool 10 prevents stock entering the delivery chambers 7 of the transfer moulding device 2.

In this position the valve spool 10 also establishes communication between the delivery chambers 7 and the recesses in the die plate 12 so that the delivery plungers which move downwardly over the crossmember 9 deliver the stock on to the conveyor belt 30 while the frame 13 and therefore the transfer moulding device 2 is lowered.

The transfer moulding device 2 is subsequently again raised into the starting position and the delivery plungers 8 simultaneously return into their original position. At the same time the valve spool 10 moves into the position illustrated in FIG. 2 in which it establishes communication between the hollow plungers and the delivery chambers 7 of the transfer moulding device 2. The connection between the delivery chambers 7 and the die plate 12 will then be interrupted.

The stock container 1 will then move in the opposite direction, that is to say towards the transfer moulding device 2, and the resultant pressure assisting the entry of stock into the delivery chambers 7. The rotation motion of the feed roller 3 is interrupted during this phase.

In the meantime the conveyor belt 30 advances by one step so that the space required for delivering further material is made available on the conveyor belt 30.

The previously described processes are then repeated in the corresponding sense.

The apparatus according to the present invention enables particularly foamy and exceptionally lightweight stock to be supplied by the shortest possible distance from the stock container 1 to the transfer moulding device 2, the stock being gently treated so as to avoid any change of its structure, volume or its quality. Delivery of the vacuum drawn stock in front of the closed delivery chambers 7 is assisted during the return from the opened delivery chambers 7 by the suction-biassed delivery plungers 8 together with the nozzle member 5 and the hollow plunger as well as the feed roller 3 so that all delivery plungers are always uniformly biassed with stock.

Steplessly variable adjustment of the length of stroke of the stock container 1 enables the magnitude of the vacuum produced thereby to be adjusted to the volume of the stock that is being processed.

What is claimed is:

1. Apparatus for delivering part quantities of foam stock and the like, comprising a stock container having an seen aelivery and; a transfer molding device; guide i-od's carried by said device and engaging said stock container; whereby said stock container is reciprocable relatively to said device; and a rotary feed roller carried by said stock container and extending into said delivery end; said device including a nozzle carried by said container and enclosing said delivery end, a hollow plunger strip slidably supported in said nozzle and having spaced parallel cylindrical bores, a plurality of delivery chambers adapted to communicate with said bores and further having a valve spool movable transversely to said bores and having ducts and parts extending transversely thereto and adapted to communicate with said bores, delivery plungers slidably mounted in said delivery chambers and a die plate carried by said device below said valve spool for the delivery of the foam stock.

2. Apparatus according to claim 1, comprising a frame, a shaft carried by said frame, pivoting levers carried by said shaft and connected with said stock container, sliding block levers engaging said shaft, and driving means connected with and actuating said sliding block levers to provide a reciprocating movement of said stock container.

3. Apparatus according to claim 2, wherein said means comprise a linkage connected with and actuating said feed roller.

4. Apparatus according to claim 3, wherein said means comprise a linkage connected with and actuating said delivery plungers. 

1. Apparatus for delivering part quantities of foam stock and the like, comprising a stock container having an open delivery end; a transfer molding device; guide rods carried by said device and engaging said stock container; whereby said stock container is reciprocable relatively to said device; and a rotary feed roller carried by said stock container and extending into said delivery end; said device including a nozzle carried by said container and enclosing said delivery end, a hollow plunger strip slidably supported in said nozzle and having spaced parallel cylindrical bores, a plurality of delivery chambers adapted to communicate with said bores and further having a valve spool movable transversely to said bores and having ducts and parts extending transversely thereto and adapted to communicate with said bores, delivery plungers slidably mounted in said delivery chambers and a die plate carried by said device below said valve spool for the delivery of the foam stock.
 2. Apparatus according to claim 1, comprising a frame, a shaft carried by said frame, pivoting levers carried by said shaft and connected with said stock container, sliding block levers engaging said shaft, and driving means connected with and actuating said sliding block levers to provide a reciprocating movement of said stock container.
 3. Apparatus according to claim 2, wherein said means comprise a linkage connected with and actuating said feed roller.
 4. Apparatus according to claim 3, wherein said means comprise a linkage connected with and actuating said delivery plungers. 